Distillate petroleum product and method of treating same



- degrees, particularly kerosene and gasoline.

.Patented Mar. 13, 1934 1,951,206

DISTILLATE PETROLEUM PRODUCT AND METHOD OF TREATING SALIE James B. Rather, Brooklyn, Orland M. Reiir, Jackson Heights, and Leslie 0. Beard, Jr., Brooklyn, N. Y., assignors to S'ocony-Vacuum Corporation, a corporation of New York Application October 29, 1928, Serial N0. 315,914

No Drawing.

10 Claims. (Cl. 44-9) This invention relates to a method of treatpaired as to their valuable and desirable qualiing' petroleum distillates with respect to disties.

A further object of this invention is to provide a method of the character referred to, which does not increase materially the cost of production of the improved products either in small amounts or on a large commercial scale, permitting the improved product to be sold to ,consumers and distributors at practically the same price as inferior products.

A further object of this invention is to provide a decolorizing agent or agents which may or may not bevariously combined, as desired, effective to deprive refined petroleum products of discoloration developed during storage and also efiective to maintain the discolored product in a colorless and odorless condition for an indefinite period.

A further object of this invention is to provide an agent or agents efiective to decolorize and color stabilize petroleum products which have developed objectionable odor or color during storage, which agents are inexpensive in first cost and inexpensive and satisfactory to apply.

Other objects of this invention will be in part obvious and in part pointed out hereinafter.

The most valuable of the material which decolorize refined petroleum distillates which have become discolored-in storage are those which render the distillate stable in color for an indefinitely long period of time after treatment. I have discovered that certain of the hydroxy compounds, such as the hydroxy benzenes and especially benzenes of' the dihydroxy and trihydroxy. groups are efiective both as decolorizers and color stabilizers. The dihydroxy benzene group includes hydroquinone, resorcinol and pyrocatechol all effective decolorizers. The derivatives of the dihydroxy benzenes, parcoloration andmore particularly to the decoloration and color stabilization of refined petroleum products such as gasoline and kerosene, which have developed discoloration or pigmentation during storage.

This application includes disclosure of inventions disclosed in our prior copending applications, to wit: Serial No. 151,005, filed November 26, 1925, now patent 1,909,985, issued May 23, 1933, Distillate petroleum products and method of treating same, and Serial No. 165,546, filed February 3, 1927, Decolorized refined petroleum products and method of producing same, and decolorized agents therefor, the present application claiming the subject matter. which has not been maintained in the claims of said applications. This application is in part a contimation of prior applications 151,005, filed November 26, 1925, now Patent 1,909,985, issued May 23, 1933, and application 165,546, filed February 3, 1927.

Refined petroleum products, especially kerosene and gasoline, on being stored are apt to develop discoloration and objectionable odor. This is generally attributed to oxidation processes going on in the oil due to the absorption of oxygen from the air. However formed, consumers and distributors of these products require that they be clear and free from discoloration and objectionable odor, as well as serviceable for the use intended.

This invention is concerned, therefore, with a process of eliminating this objectionable discoloration of stored refined petroleum products, notably those of A. P, I. gravity higher than 3'7 A further object of this invention is the production of refined petroleum products from pctroleum distillates previously discolored by internal pigmentation, which have the characteristics of being free of discoloration and of not developing objectionable color or pigmentation thereafter.

Another object of my invention is to produce water white petroleum products from various petroleum distillates having objectionable color or pigmentation which may have developed during storage, which products arein no way im- Of the trihydroxy benzenes, those especially effective are ,pyrogallol, phlorglucinol and 1-2-4 trihydroxy benzenes. 'Pyrogallol is probably the best decolorizer of the trihydroxy benzenes and is further recommended by the fact that it is easy to bring to a proper state of admixture with the product being treated.

Further efiective decolorizers and color stabilizers are naphthols or hydroxy naphthalenes, particularly alpha naphthol and beta naphthol,

ticularly orcinol are also valuable decolorizers.

thio urea, and the derivatives of thio urea, particularly thiocarbanilid. Water is often present in stored petroleum distillates and in such products handled under normal'commercial conditions. Since thiocarbanilid is less soluble in water than it is in petroleum products and is not afiectedby the water in such products, this agent is especially effective and valuable.

As a class, reducing agents, both organic and inorganic, are eifective to decolorize refined pee troleum distillates, though in the main they are less powerful in maintaing color stability. This class includes those aromatic amines which are reducing agents, for example, para phenylenediamine, ortho phenylenediame and meta phenylenediamine. Phenyl hydrazine is an ace tive reducing agent and also a decolorizer of discolored petroleum distillates. Organic acids which are reducing agents, for example, oxalic acid, and metallic soaps which are. reducing agents, for example, stannous oleate, are also effective decolorizers. Metallic soaps are valuable because of the solubility of this type of compound in petroleum products.

The'alcoholates of alkali metals which are reducing agents, for example, sodium ethylate, are also effective decolorizers. The alkali metals, such as sodium and potassium, react with alcohols, such as methyl and ethyl alcohols, with product in an exceedingly fine condition, and its solution in the product takes place much more rapidly than otherwise. Not so much of the agent should be used as will impart the color of the agent to the product. It has been found that in general one part by weight of any of the above agents mentioned to between 50,000 to 100,000 parts of product is a suitable proportion The proportion, however, varies with the ageniths with the degree and nature of the pigmentat on \to be removed, the amount of stabilization desiied the character of the distillate, i. e. its susc itfr ility to oxidation, and

the storage temperat e.\\\ So long as the preserving agent is thoroughly inixed with the product, it is not vital how the mixing is accomplished, or at what temperaturq the treatment is carried out.

the distillate and leftstanding for two hours, gavea color test of 3-18 Saybolt chromometer,

disclosing an improvement in color of 27 points.

Petroleum distillate having an initial color of the formation of 'alcoholates.- These com-.

pounds are essentially salts of the alkali metals in which the alcohol plays the part of the acid. The alkali metal alcoholates are, in general; reducing agents. The alcoholates are added to the petroleum distillates in the form of alcoholic solutions.

Among the inorganic reducing agents which are decolorizers of discolored refined-petroleum distillates, stannous chloride has proven partic-' ularly eifective. 3

The treatment is carried out by thoroughly mixing a minute quantity of. the agent or agents with the discolored product. Some of the va- 9 Saybolt chromometer, when mixed with hydroquinone in concentration of 1 part in 75,000

and left standing for four hours, disclosed a color improvement of 27 points. A petroleum distillate giving an initial color of 9 Saybolt chromometer, when saturated with orcinol and left standing for one day, improved the color of the distillate 24 points. A saturated solution of the decolorizer in the product is obtained by agitation orby percolating the product through a columnof the solid decolorizer whereby the product is saturated with thedecolorizer. A

saturated solution of orcinol in petroleum distillates varies from one part to 50,000 to from one part to 100,000 parts of distillate.

rious agents require different lengths of timeafter mixingwith the discolored product before the color due to pigmentation and objectionable odqr is removed.

The agents above named which occur in solid form, such, for example, as hydroquinone, pyrogallol and thiocarbanilid, are preferably first dissolved in a suitable solvent which is miscible in the product under treatment. The solvents most effective for, hydroquinone and pyrogallol are the aliphatic. alcohols, for instance ethyl, butyl or iso-propyl alcohol. Acetone is the preferred solvent for thiocarbanilid.

It will be understood, however, that the products to be treated may also be p'ercolated through a mass of the above agents within the contemplation of this'invention. In using such. solids as oxalic acid or stannous chloride it has been found advantageous to percolate the product being treated through a column of the solid. Petroleum distillate will onlyabsorb a limited amount of these decolorizing solids beforethe saturation point is reached, and the process is carried on at ordinary temperatures, there is no danger of the product absorbing an'ob- A saturated solution of beta naphthol in petroleum dfstillate giving an initial colortest of 15 Saybolt chromometer, after standing for five days, disclosed a color improvement of 33 points. A saturated solution of thio urea in petroleum distillate giving an initial colortest of -15 Sayboltchromometer, after standing for iectionable or quality impairing quantity of the same. Stannous oleate is an; oily solid, and it may be added as such during violent agitation of the oil being treated. i 7

When a solution of the above character is mixed with the petroleum distillate under treatment, the agent used becomes dispersed in the 14,days, noted a color improvement of 33 points. When thiocarbanilidwas mixed with a petroleum distillate having an initial color of 9 Saybolt chromometer, in concentrations of 1 part in 75,000, after standing for 5 days a color improvement of 22 points was noted.

A petroleum distillate having an initial color of 15.$ay%l t chromometer, when saturated with para phenylene-diamine and left standing for five days, showed a color improvement of 25 points. 'A petroleum distillate of initial color -15 Saybolt chromometer, when saturated with phenyl hydrazine and left standing for one hour disclosed a color improvement of 34 points. Petroleum distillate having an'initial color of 9 Saybolt chromometer, when treated with oxalic acid and left standingfor one day, disclosed a color improvement of 16 points. c

Petroleum distillate giving aninitial color testof 25 Saybolt chromometer, when'satu rated with stannous oleate and left foroneday, improved incolor 41 points. Petroleum distillate giving an initial color test of --9 Saybolt chromometer, when saturated with sodium methylate and left standing for one day, improved incolor 27 points. Petroleum distillate giving an initial color test of 25 Saybolt chromometer, when saturated with stannous ,150

propyl or secondary butyl alcohol.

chloride and left standing for one day, disclosed a color improvement of 43 points.

, As an example of the practice of this invention, a 10% solution may be made, for instance, of pyrogallol in isopropyl alcohol, or five pounds of pyrogallol is dissolved in five gallons of iso- The addition of one part of this solution to 10,000 parts of the petroleum product, that is, one part of pyrogallol to 100,000 parts of product, is suincient. If the product is only slightly discolored one part of pyrogallol to 150,000 parts of product suffices. The addition of the pyrogallol solution to the product is made gradually, and in such increments that the ratio of the pyrogallol solu-' tion to the amount of product that is being treated shall preferably be in a ratio predetermined by test.

After thorough mixing of the discolored distillates and the agent has been accomplished, the resulting product is conducted into a clean, dry tank, where it is allowed to stand until sufficient time has elapsed for the reaction between the pyrogallol and the pigmentation in the product to be completed. With many of the above agents and at ordinary temperatures, 24 hours usually suffices for this reaction to clear the product as to color and objectionable odor. At more elevated temperatures, generally, a shorter time will be required. During'this treatment the product should be kept dry and the treated product should be kept out of con-.

tact with water, since many of the above agents are more soluble in water than in the product, and the water may tend to dissolve the agent and result in the return of some discoloration. Thiocarbanilid is an exception, being more soluble in oil than water, as above pointed out, and thus becomes a very valuable discolorizer in treating petroleum distillates contaminated with water.

Petroleum products decolorized by this method are invariably more stable than originally, due-to the continued presence 05 the preserving agent. The products are novel in that they have the characteristic of not developing color at least for some time after being stored.

The above-mentioned substances 'are generally suitable either alone or in combination with others. It is neverrequired to ,add' more than 0.02% to the kerosene or gasoline and the amount may be so small as one part of agent to 200,000 parts of such product.'

In view of the factthat kerosene and gasoline must be maintained comparatively inexpensive in order to satisfactorily cope with commercial competition, any treatment must be such that the cost of production is not increased a prohibitive amount. The method herein disclosed satisfactorily meets this requirement since the amounts of any of the above agents used which the treatment requires are so small that increase in the-cost of manufacture and price to'the consumer is negligible. At the same time the treated kerosene and gasoline is free from discoloration and may be stored and handled without danger of its becoming discolored or odorous.

As many changes could be made in the process described, and as many apparently widely different embodiments of this invention could be made without departing. from the scope thereof, it is understood that all matter contained in the above description shall be interpreted as illustrative and not a sense..;..

What we claim is:- r 1. The process of treating light colored distillate petroleum products of the class of gasoline or kerosene, which products have become discolored, which comprises adding to said discolored product a polyhydroxy benzene in quantity sufiicient to effect substantial decolorization of said product and substantially to retard subsequent discoloration of said product.

2, The method of decolorizing and stabilizing a low boiling point petroleum distillate product of the class of gasoline or kerosene that normally tends to become discolored, which comprises adding to said discolored product a quantity of a polyhydroxy benzene in the proportion of not more than 0.01% but sufiicient to effect substantial decolorization of the product and substantially to delay subsequent objectionable color formation. V

3.. The process of treating light colored distillate petroleum products of the class of gasoline or kerosene, which products have become discolored, which comprises adding to said discolored product a trihydroxy-benzene in quantity sufficient to effect substantial decolorization of said product and substantially to retard subsequent discoloration of said product.

4. The method of decolorizing and stabilizing a low boiling point petroleum distillate product of the class of gasoline or kerosene that normally tends to become discolored, which comprises adding to said discolored product a quan tity of a trihydroxy benzene in the proportion of not more than 0.01% but sufficient to effect substantial decolorization of the product and 110 substantially to delay subsequent objectionable color formation.

5. The process of treating light colored distillate petroleum products of the class of gasoline or kerosene, which products have become 5 discolored, which comprises adding to said discolored product pyrogallol in quantity suflicient to effect substantial decolorization of said product and substantially to retard subsequent discoloration of said product.

6. The method of decolorizing and stabilizing a low boiling point petroleum distillate product 'of the class of gasoline or kerosene that norline or kerosene, which products have become discolored, which comprises adding to said discolored product phloroglucinol in quantity sufficient to effect substantial decolorization of said product and substantially to retard subsequent discoloration of said product.

8. The method of decolorizing and stabilizing a low boiling point petroleum distillate product of the class of gasoline or kerosene that normally tends to become discolored, which comprises adding to said discolored product a quantity of phloro glucinol in the proportion of not more than 0.01% but sufficient to efiect substantial 145 decolorization of the product and substantially to delay subsequent objectionable color formation.

9. The process of treating light colored distillate petroleum products of the class of gasop 1,951,206 line or kerosene, which products have become.

prises adding to said discolored product a quantity of l2 4 trihydroxy benzene in the proportion of not more than 0.01 butsufilc'ient to effect substantial decolorization of the product and substantially to delay subsequent objectionable color formation.

JAMES B. RATHER. ORLAND M. REIF'F. 'nssnm c. BEARD, Jn. 

